High impedance surfaces are generally known. Such surfaces are generally used with antennas for generating signals that carry information to other remote devices. Another application includes use as an electromagnetic wave reflector. High impedance surfaces can have a variety of operational characteristics, which are based on the physical makeup of the high impedance surface, such as the size, shape, physical arrangement, and electromagnetic properties of the various conductive elements that comprise the high impedance surface. It is also known that varying the physical arrangement or electromagnetic properties of the surface changes the operational characteristics in a known manner.
For instance, high impedance surface antennas typically operate in a relatively narrow frequency band. The frequency band in an antenna application is dependent on the effective inductance and capacitance between the conductive elements. If this capacitance and/or inductance is varied, the surface's operating frequency is similarly varied. As such, varying the properties of the surface in a known manner, for example, can allow a user to create a surface with tunable properties.
Although a high impedance surface can function as an antenna, by other approaches a high impedance surface is often used with an antenna, in place of a conventional ground plane. A ground plane is usually part of an antenna design. In a cell phone, for example, the circuit board acts as a ground plane to the antenna. In such configurations, high impedance surfaces can provide additional functionality to the antenna.
Micro-electromechanical switches, commonly referred to as “MEMS,” are also generally known in the art. MEMS switches are typically fabricated on silicon substrates, and then packaged to form a component that can be surface mounted on a printed circuit board. In another approach, MEMS switches are fabricated as integral parts of the printed circuit board; this allows circuit board manufacturers to create a large number of switches on a circuit board without having to surface mount or solder separate elements on the circuit board. Integral MEMS switches can be created on a circuit board at high volumes at relatively small incremental price increases. It is generally difficult, however, to reliably have all of the micro-electromechanical switches in a given application working properly, due to typical manufacturing yields when components are mass formed. MEMs switches fabricated as an integral part of a printed wiring board or circuit board utilizing organic based printed wiring board build-up materials are typically referred to as Meso-MEMs switches.
Furthermore, known attempts to surface mount micro-electromechanical switches or other electrical components onto high impedance surfaces to provide variable electromagnetic properties for the surface used methods that are costly, time consuming, and unreliable. Such known arrangements typically fail to provide fully integrated and controlled switches for satisfactorily varying the electromagnetic properties of the high impedance surfaces.
Skilled artisans will appreciate that elements in the figures are illustrated for simplicity and clarity and have not necessarily been drawn to scale. For example, the dimensions and/or relative positioning of some of the elements in the figures may be exaggerated relative to other elements to help to improve understanding of various embodiments of the present invention. Also, common but well-understood elements that are useful or necessary in a commercially feasible embodiment are often not depicted in order to facilitate a less obstructed view of these various embodiments of the present invention. It will further be appreciated that certain actions and/or steps may be described or depicted in a particular order of occurrence while those skilled in the art will understand that such specificity with respect to sequence is not actually required. It will also be understood that the terms and expressions used herein have the ordinary meaning as is accorded to such terms and expressions with respect to their corresponding respective areas of inquiry and study except where specific meanings have otherwise been set forth herein.